Star-disk roller bit



April 18, 1939; J. A. ZUBLIN 2,154,554

STAR-DISK ROLLER BIT Filed Aug 29. 1938 (/0171? A. Zab/ff? Arrop/vsy ..-.;Psienisd A r. 18, 1939 more particularly to -that class plications.

i. sites eras-men norms arr v 'Thls invention re'lates drilling I of is used in the rotary of *wells:- and still I more specifically to the type tools described in States Patents Nos. 2,050,988, 2,050,989, 2,069,795, 2,069,796, 2,069,797, 2,069,798, 2,069,799," 2,079,142, 2,118,542 and 2,126,079; and'in many'of my United Staiesap- Specifically, the present invention is more closely -related with theiappiication's referred to.- In Patent No. 2,126,079,, the invention .described therein is concerned with the use of disks which are in rolling contact with the formation, being especially adaptable for'making e'fllcient drilling progress in hard formations; -Although the extent of penetration of each is greater than is obtainable with corresponding star rollers. under some conditions of operation'the disks do not turnireely about their own respective axes. This is probably due tothe 'factthat the turning force of engagement between the disks and the formation-is of insuiiicient magnitude to overcome the bearing friction betweeneach'roller and its supporting pin; Especially does this occur whena plain friction type of bearing is used; As soonsequence of the inability of the disks to turn freely on their bearing'suppor'ting pins, their cut-. ting edges will slide "over the formation and become flattened. Ihis will provide "additional resistance to the turning of -the cutters about their own .rwpective axes since the flatteninglwill in-' troduce an additional sliding 'of the disk the formation preventing-its rollingiaction inxthe. manner intended and aggravating theflattened condition. V a

It is further desirable that the disks bemaintained free from cuttings in order that'they can penetrate the formation lwithout' being impededv by detritus eaked on ,and between their cutting d es t. In Pa ent No.2.;11 ,5: ,-an inclined? upper nozzle is both described and claimed havingamong its purposes the rotation of. thecutters as they move into the line of action of the fluid issuing from the nozzle. When starrollers are used the fluid stream can impinge upon the cut,- ting teeth in much the same manner aswater. can act upon .the buckets of a water wheel, and due toits impact with the teeth, cause rotation of the, rollers. However, in using disk rollers, theturning effort of the, fluid streamupon the disks is limited to the friction of the-fluid as it encounters the side faces of the disks. This force 7 is probably insuflicient in producing rotation of the disksiso that all of theircuttingedges are will be understood by reference tothe following ofFigurel;

their entire earthcontacting portions. The ad- Wbn M22173; 1 h v not acted upon by the passes under-1t 1 a a In its essential aspects the present invention; is with'overcoming the above noted =-fluidstream scene's roller diiflculties; Accordingly, it becomes an object of s I this invention to insure rotation of the disks while they areiiicor'itaiat with the formation, thus preventing flattening of their cutting edges'and obtainin'g uniform' wear thereon so that during theeflective life ofthe-drilling-tool the cutting 10* edges of'each disk will be substantially equidistant from theaxisof the cutter.

A further object of the invention is to provide instrumentalities :operable in conjunction with disks to thorough-cleaning of the disks by virtue of their rotation by fluid issuing from a: cleaningnozala r v A further object of. the invention resides'in the provision sofa composite rollerppreferably' in-:

cluding both disks and teeth, .which"-wil1' conform tothe'outline produced on the hole bottom and which-willinsurerotation of the-disks while'they';

are in contact with the formation. 7

- How these objects and others are obtainable description and the annexed drawing, in which: Figure 1 is'apartial sectionon'the linei--l of Figure 2: and

-Figurej2 is a partial section onthe. line 2-4 In its'g'eneral aspects, the invention contemplates the use of rolling disk cutterswhich will produce amoreeflectivebreakdown of the for-' mation than roller cutters having teeth over vantages ofgusing disks have been described in. myapplicationentitled .Biolling disklbits'l. The present invention contemplates taking the beneilts associated withrollingdisks while overcoming their disadvantages; In furtherance of thisend, each roller isa composite of'a disk and a star roller, the teeth on the stariportions in efiect gearing .themselvesvto the formation so that the.

, entire roller is caused to; rotate "about its own axis at .all times while in formation contact, there-by overcoming, the tendency of the disks to be arrested by virtue of the bearingfriction be tween it and its supportingpimv Furthermore, fluid issuing from a: cleaning nozzle will first engage against the teeth on thestar'portions of the roller, causing the roller to rotateand by the kinetic energystored therein the roller will continue to rotate while thedisk portions pass under the fluidstream. In this manner there is assurance that the entire cutting surface on each attached to a drilling string for rotation about The lower diskwillbeacteduponandcieanedbythe fluid stream I a generally longitudinal axis A-A. portion of the shank is quipped with two depending legs l2 carrying between them the cutter carrier ll. About the periphery of the cutter carrier is rotatably mounted a plurality of roller cutters ll comprlsingdisk portion Ila and toothed star portions I lb.

As described in my Patent No. 2,079,142, the carrier is 'rotatably mounted between the shank legs by means of bearing member I! which conll screwed into each end of the bearing sleeve. The carrier has an inner cylindrical surface" rotatably mounted on the. sleeve, and inclined surfaces is complementary to the flanges. Between the flanges and these inclined surfaces are ballbearings which serve to transmit part of i the radial load on the carrier-and allof the axially parallel loads.

0n the outer'surface of each flangeis provided .araisedboss2l whichisinsertedintoatransverse slot 22 formed .in each of the legs of the shank.

The bosses are flattened across their top and. bottom sides 23, ll in orderthatthey can be slid" into the slots in the legs and be held from rotating relatively thereto. --Relative rotation between the flanges is prevented by means of a locking pin 21- The entire assembly is attached to the legs of the shank and held "in proper position by tapered pins ll which are externally threaded at 21, cooperating threads being-supplied in each flange. pins is prevented by insertingcotter keys 2! through a. bore 29 in each pin, the legs of each pin being .bent'back to engage with casteliatio'ns 3| in each pin and with slots II in theshank,

Tolubricate the bearing surfaces, passageways 32 for the-circulatingfluid are supplied at intervals around the carrier. These passageways will convey the fluid from each roller cutter to the bearing surface.

As explained in my Patents Nos. 2,050,988 and 2,069,799, a drilling tool of the type Just described will have its cutters brought intermittently into and out of contact. with the formation being operated upon. 'Thus, each cutter has three degrees of freedom of. motion, namely, revolution about the .axis A-A of the hole, revolution about the inclined-axis 3-38 of the carrier, and rotation about itsown axis, which is'the axis of theepins 31 directly supporting eachcutter. Each cutter will tracea generally spiral path upon aconcaveor hemispherical bottom of the hole produced by drill bits of this type. This is due primarily to 1 cutter will be moved successively out of contact with'the formation and will be positioned under a fluid nozzle ll threaded into the shank and communicatingv with the fluidapassage a contained therein.

It will be noted that each roller is" mounted on the carrier so that its star portion llb ispositioned ahead ofthe disk portion Ila as regards carrier rotation. As seen in Figure 1, the

Removal of the tapered;

. of the roller because of the frictionof the fluid against the side faces of each disk. The arrangement shown and described thereby provides assurance that all partsof the composite roller will be maintained free from cuttings.

sists of a central cylindrical sleeve ll and flanges between the rollers and their supporting pins 81 might in some instances be sufllcient to arrest ro- 'As was indicated above, the bearing friction tation -of the;roller on the pin .;and resultin a sliding action of the: disks on. .the formation and their j consequent However, the toothed starportionilb of each-roller will con:

tact with the formation and become functionally geared thereto while moving in its spiral path along the hole bottom., Inthis respect, positions ing the star, in advanceof'the disk portions as ly. and eliminating any tendency of thedisk to slide on the formation or to become arrested prior to aasubsequent. engagement of the star roller portion, which might occurwere the toothp'or tion positioned rearwardlyof the disks as regards carrier rotation 1 Although in:Figure lr-all of the star portions: have been shown as being positioned ahead of the disk portions as regards. carrier rotation, to

eliminate anytendency towards tracking, the disk portions mightbe positioned-ahead of the star portions on only some-of the rollers. Alternate .rollers can have their star, portions, positioned before the disks, the other rollers having disk portions ahead of :the star portions. Itwill be 1 noted further that the teeth onthe star portion can beshapedto extend parallelto the'roller axis or they can be inclined with respect. thereto; as by forming them geneli l like helical gear teeth. Aiso each disk may extend perpendicularly with the roller axis or it can make anangle therewith as by forming the disklike a helical thread of relatively steep pitch, or of cup shape To maintain all of the disks on each cutter and the starteeth insubstantially simultaneous contact with the formation, each roller cutter is shaped to conform to the g'enerally hemispheri L cal surface produced at the bottom of the hole.

This is accomplished by shaping each cutter with its disk edges and-the star tooth ends'lying on a surface of barrelshape, the curvature of the surface having substantially the same radius as the radius of the hemispherical hole bottom. The

carrier will rotate-in a.v clockwise direction to drilling tool is thereby attended with a smooth operation. I

The drilling tool described combines the advantages of disks, as regards their ability to cut certain types of formations that cannotbe effectively penetrated by rollers toothed along their entire formation contacting portions, and of star rollers, which'can remove other types of formation eflectively by an impact action. This makes the tool morenearly universal in its application to the making of holes in various types of hard formation", in addition to eliminating the disadvantages associated with drilling tools'using disks entirely and those using star rollers entirely.

It will be understood that my invention may be embodied in various forms and that the spe-' cific illustration on the drawing is to be construed as an example of the invention rather than as imparting any limitations thereon; and that various changes can be made without departing from the invention so long as they fall within the scope of the claims appended hereto.

I claim:

1. An earth boring tool comprising a shank,

one or more rollers rotatable with respect to said shank, and means mounting said rollers on said shank for intermittent contact with the formation, at least one of said rollers having disk cutters with continuous circumferential cutting edges on a portion thereof and toothed cutters said carrier, each roller having one or more disk cutters on a circumferential portion thereof and toothed cutters on another circumferential portion thereof in advance of said disk cutters as regards the direction of carrier rotation on said shank.

4. An earth boring tool comprising a shank, a cutter carrier rotatably mounted on said shank,

a plurality of rollers rotatably mounted on said carrier, and fluid means on the shank adapted to effect a cleaning of the rollers, each roller having one or more disk cutters on a portion thereof and tooth cutters on another portion thereof in advance of said disk cutters as regards the direction of carrier rotation on said shank, whereby said toothed cutters will be acted upon by ,fiuid issuing from said fluid means prior to said disk cutters to rotate and clean the roller cutting portions.

5. An earth boring tool comprising a shank, a cutter carrier rotatably mounted on said shank, a plurality of rollers rotatably mounted on said carrier, and fluid means on the shank adapted to effect a cleaning of the rollers, each roller having one or more disk cutters on a circumferential portion thereof and toothed cutters on another circumferential portion thereof in advance of said disk cutters as regards the direction of carrier rotation on said shank, whereby said toothed cutters will be acted upon by fluid issuing from said fluid means prior to said disk cutters to rotate and clean the roller cutting portions.

6. An earth boring tool comprising a shank, one or more rollers rotatable with respect to said shank, and means mounting said rollers on said shank for bodily translation with respect to said shank, at least one of said rollers having disk cutters on a circumferential portion thereof and toothed cutters on another circumferential portion thereof. v I

7. An earth boring tool comprising a shank, one or more barrel-shaped rollers rotatable with respect to said shank, and means mounting said rollers on said shank for bodily translation with respect to said shank, at least one-of said rollers having disk cutters on a circumferential portion thereof and-toothed portions on another circumferential portion thereof.

, 'JOHN A. ZUBLIN. 

